In general, an air-conditioning apparatus uses a refrigeration cycle formed by a compressor, a condenser, an expansion valve, and an evaporator connected in series via refrigerant pipes. In the refrigeration cycle, low-pressure gas refrigerant sucked into the compressor is compressed to predetermined high pressure, then led to the condenser, and turned into high-pressure liquid refrigerant by exchanging heat with air. The high-pressure liquid refrigerant is led to the expansion valve to be expanded therein, then sent to the evaporator as low-pressure, two-phase gas-liquid refrigerant, turned into low-pressure gas by exchanging heat with air, and sucked into the compressor and compressed again, thus circulating in the above-mentioned refrigeration cycle.
In some of such air-conditioning apparatuses, for example, a single outdoor unit is connected with two or more indoor units. In this case, it is necessary to distribute refrigerant equally to all the indoor units. In particular, during cooling operation of the air-conditioning apparatus, because the refrigerant introduced into an indoor unit equipped with an evaporator is in a two-phase gas-liquid state or in a liquid-phase state, it is important in maintaining performance of a heat exchanger to distribute liquid-phase refrigerant and gas-phase refrigerant equally to all the indoor units.
Thus, a refrigerant distributor is proposed in which notches are provided in end faces of plural branch pipes inserted into an introduction pipe through which refrigerant flows and the notches receive the flowing refrigerant, thereby allowing the refrigerant to be distributed equally to all the branch pipes (see, for example, Patent Literature 1).
On the other hand, a refrigerant distributor is proposed in which one end of an adjusting pipe is connected to a connecting member between a refrigerant pipe and a diversion pipe while an other end of the adjusting pipe is closed, which allows refrigerant to be stirred at the closed other end of the adjusting pipe, thereby equalizing the refrigerant flowing through the diversion pipe (see, for example, Patent Literature 2).